Factors Influencing on Postural Balance and Voluntary Movement in Individuals With Acute Stroke

Background

Postural control is an important component of movement. Prior to movement initiation, it is necessary to control posture such as gait initiation. Individuals with stroke often show impairment in both postural control and voluntary movement. The deficiencies restrict individuals with stroke to perform activities daily living and reduce quality of life leading to a great burden on family members and healthcare system. Additionally, there are positive association between postural control and movement. Therefore, postural control influences movement in individuals with stroke that may be in long term.

Factors influencing on postural control and voluntary movement are shown in subacute and chronic phase of stroke. Previous stroke, age, bowel incontinence, visuospatial problem, initial severe hemiplegia, lesion edema, and intraparenchymal bleeding can predict postural control. Static and dynamic postural balance can predict functional outcome and discharge destination, as well as independent ambulation in individuals with stroke. Level of paresis, motor-evoked potentials, and size of lesion can predict voluntary movement. Furthermore, baseline upper extremity (UE) voluntary movement, hemorrhagic stroke, baseline National Institutes of Health Stroke Scale (NIHSS), and cortical lesion excluding primary motor cortex can predict outcome of UE movement in subacute stroke. Admission lower extremity (LE) voluntary movement score and volume and edema of lesion are predictors for motor recovery of LE at discharge from rehabilitation ward. Age, severity of LE weakness, visual problems, size of lesion, and type of stroke are predictors for walking ability within 30 days after stroke.

Those factors associating with postural control and voluntary movement were studied in subacute and chronic phase of stroke, but not in the acute period. The findings may limit to apply to the earlier period of stroke since different mechanisms of recovery occurring in different timing after brain injury. Additionally, in clinical practice, one of the common questions that clinicians are often asked by individuals with stroke and family members is whether he/she can sit, stand, and walk. To provide an assurance response, the factors associated with postural control and voluntary movement in the acute phase of stroke is required.

Furthermore, previous studies investigating predictors of postural control and voluntary movement used diverse outcome measures. Posture control were examined by different measures, for example Barthel Index, Mini-Mental State Examination, Frenchay Activity Index and Rankin Scale. Similarly, motor function recovery was assessed by various outcomes such as Scandinavian Stroke Scale, Medical Research Council scale, Motricity index, and exclusive of own scale. These measurements indirectly assessed postural control and voluntary movement. However, there is a measure directly examining postural control and voluntary movement for individuals with stroke that is Postural Assessment Scale for Stroke (PASS) and Stroke Rehabilitation Assessment of Movement (STREAM). These two measurements have excellent reliability and show no floor or ceiling effect in acute stroke. In addition, the PASS is an outcome measure recommended for acute stroke care. It would be, therefore, better using PASS and STREAM to record and for communication.